Merge branch 'adam-time'

Replace time() calls with monotinic version from libwr
Fix bug 1164 and similar problems in other programs.

It was possible that SNMP objects in expert branch don't update.
It pop-up in following scenario:
  1. slave switch is started with no ntp configured
  2. read via snmp from slave
  3. master switch is started with no ntp configured
  4. slave sync to master and set it's time, by this system clock on slave is set
     to earlier date
  5. read via snmp from slave will end up in the same results in expert branch of
     the MIB.

Signed-off-by: Adam Wujek <adam.wujek@cern.ch>